In recent years the proliferation of convenience or fast food restaurants has driven a growing need to handle, recycle, store, screen, and dispose of fats generated from the fryers in such restaurants in the form of used cooking oil and fats generated by the cooking grills as a byproduct of heating and cooking meats and products containing fat.
Previously, when disposing of oil, a bucket or container was used to collect the oil for transport to a container where it is held for collection by a truck. Such a method exposed the person doing the transport to a risk of burns, and it also allowed spillage onto the floor from the open bucket.
Recently, there have been developed wheeled transport devices for disposing of used cooking oil from the fryers, socalled "grease caddies" of low slung design and having a pivotable top lid openable to expose a screened filter basket. The grease caddie is adapted to the fryer-cookers so that the caddie fits into the space below the hot oil fryer-cooker such that the oil can be drained by gravity from the cooker through the screening basket into a reservoir in the caddie.
In the instance of disposing of the fats generated from the cooking grills, troughs or removable trays are filled with run off fats and particles from the high temperature heating or cooking surface known as the grill. The contents of these trays are periodically dumped into the disposal buckets.
Prior art disposal caddies consisted of carts of various shapes and sizes with wheels designed to roll the cart to a disposal receptacle, whereupon the contents are hand or electrically pumped from the cart into the disposal container.
It is clear that an improved apparatus for handling, screening and, in this case, heating the fats is desirable. Heating of fats held in the disposal cart is needed because at room temperature fats thicken or even solidify, which makes evacuating the contents of the disposal container cumbersome and difficult. Heating capacity in the disposal cart provides greater flexibility and convenience for the operator because the operator can control the temperature of the fat which, in turn, allows the convenience of pumping the hot, liquid fats from the cart at a time most convenient for the operator.
The more recently designed grease caddies included a heater element inserted directly into the tank of the caddie to maintain the contents of the caddie fluid for pumping out into large storage tanks, or if the contents had solidified, to liquify the contents for evacuation.
The problem with these heat devices is that they were implanted into a small area of the caddie tank and the heater would have to be operated at a high enough temperature for the warmth to spread throughout the caddie, thus liquefying the entire contents thereof. Such elevated temperatures, plus the direct contact between the heating element and the grease or oil in the tank caused its own set of problems. On certain occasions, especially when the contents of the tank was low, the grease might smoke or even catch fire due to exposure to too much heat.
While a thermostat could in theory be used in an attempt to control the temperature, having the heating element directly exposed to the grease or oil left much to be desired. After considering the situation noted above, it became clear to the inventor that there was a better way to maintain the grease fluid without adding to the cost or complexity of the caddie (as via a thermostat) and while also eliminating the grease--heating element contact.